Generally, a semiconductor package manufacturing process is largely divided into a preprocess, a postprocess and a test process. The preprocess is also referred to as a fabrication (FAB) process, which is a process of forming an integrated circuit on a wafer of a single crystal silicon material. The postprocess is also referred to as an assembly process, which is a process of forming an integrated circuit package (device under test) by dividing the wafer into individual chips, connecting a conductive lead or ball to the chips to make connection of electrical signals to external devices possible, and molding the chips with resin such as epoxy resin to protect the chips from the external environments. The test process is a process of testing whether the integrated circuit package normally operates, and separating good and bad products.
One of core components applied to the test process is a socket. The socket is mounted on a printed circuit board (PCB) electrically connected to a tester for testing an integrated circuit and is in charge of a function of electrically and mechanically connecting the tester and a handler. Here, contact pins of the socket are in charge of a function of electrically connecting a lead of the integrated circuit package and a terminal of the printed circuit board.
The tester creates an electrical signal for testing an integrated circuit package that will be mounted on the socket, outputs the electrical signal to the integrated circuit package, and tests whether the integrated circuit package normally operates using the electrical signal inputted through the integrated circuit package. As a result, the integrated circuit package is determined as a good or bad product.
The handler automatically mounts the integrated circuit package on the socket, withdraws the integrated circuit package from the socket according to a test result of the tester, and disposes the integrated circuit package after determining the package as a bad or good product.
Meanwhile, the price of testers increases recently due to increase of devices under test (DUTs) simultaneously tested for the sake of high speed, high functionality and high productivity of the integrated circuits. To efficiently use the expensive testers, it is very important to select and use an appropriate socket and manage the lifespan of the socket.
If lifespan of a socket is exhausted and performance of the socket is degraded while testing a large quantity of packages, the cases of classifying a semiconductor package of a good quality as a defective one gradually increase, and a very high defective rate is maintained until the defective socket is replaced with a new socket. In addition, as the expensive tester and the handler should be stopped to replace the socket whenever a defective socket is replaced, efficiency of the test is lowered, and as a result, and this may affect the production yield.
To prevent this problem, in the semiconductor industry, gradual increase of the defective rate is prevented by replacing a defective socket with a new socket when a socket reaches a predetermined number of times of using the socket, i.e., a threshold use count, and an appropriate replacement time is managed by grasping the number of good products and bad products, together with the threshold use count. Meanwhile, the replaced socket may be reused through a test after cleansing the socket.
The methods currently used in the semiconductor industry to grasp the threshold use count, the number of good products and the number of bad products as described above will be described below. Although a method of approximately estimating the number of times of using a socket by recording an initial use date on the socket body and grasping the time elapsed from the date is used as a first method, this method may not calculate an accurate data, and it is impossible to grasp all the necessary items such as the number of times of using the socket, the number of good products, the number of bad products and the like. As a second method, there is a method in which the tester or the handler memorizes the data processed by each socket. However, this method may not acquire accurate data as the position of a socket may not be recognized when the position of the socket is changed, and there is a problem in that it is unable to identify the number of times of using a socket reused through a reproduction work such as a cleansing work or the like described above.